RESUMEN
Since pepc gene encoding phosphoenolpyruvate carboxylase (PEPCase) has been cloned from Anabaena sp. PCC 7120 and other cyanobacteria, the effects of pepc gene expression on photosynthesis have not been reported yet. In this study, we constructed mutants containing either upregulated (forward) or downregulated (reverse) pepc gene in Anabaena sp. PCC 7120. Results from real-time quantitative polymerase chain reaction (RT-qPCR), Western blot and enzymatic analysis showed that PEPCase activity was significantly reduced in the reverse mutant compared with the wild type, and that of the forward mutant was obviously increased. Interestingly, the net photosynthesis in both the reverse mutant and the forward mutant were higher than that of the wild type, but dark respiration was decreased only in the reverse mutant. The absorbance changes of P700 upon saturation pulse showed the photosystem I (PSI) activity was inhibited, as reflected by Y(I), and Y(NA) was elevated, and dark reduction of P700(+) was stimulated, indicating enhanced cyclic electron flow (CEF) around PSI in the reverse mutant. Additionally, the reverse mutant photosynthesis was higher than that of the wild type in low temperature, low and high pH, and high salinity, and this implies increased tolerance in the reverse mutant through downregulated pepc gene.
Asunto(s)
Adaptación Fisiológica/genética , Anabaena/genética , Ambiente , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos , Complejo de Proteína del Fotosistema I/metabolismo , Estrés Fisiológico/genética , Respiración de la Célula , Oscuridad , Regulación hacia Abajo/genética , Transporte de Electrón , Vectores Genéticos , Concentración de Iones de Hidrógeno , Mutación/genética , Fotosíntesis , Complejo de Proteína del Fotosistema II/metabolismo , Teoría Cuántica , Salinidad , Temperatura , Regulación hacia Arriba/genéticaRESUMEN
To investigate the function of a bacterial-type phosphoenolpyruvate carboxylase (PEPC2) derived from photosynthetically-grown Chlamydomonas reinhardtii, a fragment of the pepc2 gene was cloned and expressed in Escherichia coli. After optimal induction for 6 h, PEPC activity in the reverse mutant was lower than wild type (0.9 vs. 1.7 U/mg protein), and soluble protein was also lower than wild type (119 vs. 186 mg/g dry wt). In contrast, the total lipid content was increased from 56 (in wild type) to 71 mg/g dry wt, despite the growth rate being slightly diminished. The changes in PEPC activity, soluble protein and total lipid in the forward mutant were the opposite (2.4 U/mg, 230 mg/g, and 44 mg/g dry wt, respectively). Together, these data indicate that PEPC may function as a metabolic pivot in the regulation of protein and lipid accumulation in this alga.
Asunto(s)
Chlamydomonas reinhardtii/enzimología , Chlamydomonas reinhardtii/genética , Fosfoenolpiruvato Carboxilasa/genética , Fosfoenolpiruvato Carboxilasa/metabolismo , Proteínas Algáceas/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Metabolismo de los Lípidos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Genética InversaRESUMEN
OBJECTIVES: To investigate the safety and efficacy of yangxinkang tablets in patients with chronic heart failure (CHF) and syndrome of qi and yin deficiency, blood stasis, and water retention. METHODS: In a double-blinded, randomized, placebo-controlled, multicenter clinical trail, 228 patients with CHF New York Heart Association (NYHA) class II or III in stage C were assigned by randomized block method to two groups in a 1:1 ratio to undergo either conventional Western treatment or conventional treatment plus yangxinkang tablets for 4 weeks. The outcome measure were effect of cardiac function, Chinese medicine (CM) syndromes, scores of symptoms, signs, and quality of life measured by Minnesota Living with heart failure questionnaire (MLHFQ) before and after the treatment. RESULTS: Totally 112 patients were analyzed in the treatment group and 109 in the control group. They were comparable in NYHA functional class, basic parameters and primary diseases before treatment. Cardiac function and CM syndromes were greatly ameliorated in both groups after treatment. Total effective rates of cardiac function and CM syndrome in the treatment group were significantly higher than those in the control group (P<0.05). Total symptom score and sign score in the treatment group decreased significantly after treatment (P<0.01), which were significantly lower than those in the control group (P<0.05). There were statistically significant differences in post-treatment scores of gasp, cough with phlegm, pulmonary rales and jugular vein engorgement between the two groups (P<0.05 or P<0.01). Three MLHFQ scores decreased significantly in both groups after treatment (P<0.01). Post-treatment total scale score and physical subscale score in the treatment group and the reduction of them showed statistically significant differences (P<0.05) as compared with the control group. There was no significant difference between the two groups in emotional subscale score and the reduction after treatment (P>0.05). There was no obvious adverse reaction in either group noted during the study. CONCLUSIONS: Yangxinkang tablets were safe and efficacious in improving cardiac function, CM syndromes, symptoms, signs, and quality of life in patients with CHF class II or III in stage C on the base of conventional treatment.
Asunto(s)
Medicamentos Herbarios Chinos/administración & dosificación , Insuficiencia Cardíaca/tratamiento farmacológico , Anciano , Enfermedad Crónica , Método Doble Ciego , Femenino , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Calidad de Vida , Encuestas y Cuestionarios , ComprimidosRESUMEN
OBJECTIVE: In order to study the effect of the polymorphism at the exon2 region of the (3-LG allele gene on milk composition and yield. METHODS: The single-strand conformation polymorphism method (PCR-SSCP) was used to analyze for polymorphism the exon2 region of the 3-LG gene (NCBI accession number: DQ489319) in Chinese Holstein. RESULTS: Eight SSCP patterns were detected in the fragments: ab, abc, abd, abe, abcd, abce, abde and abcde, and the patterns frequencies as follows: 0.14, 0.10, 0.27, 0.23, 0.05, 0.04, 0.11 and 0.06 (P < 0.05); Six single nucleotide polymorphism (SNP) were detected in this study: sitel C>T, site2 T>C, site3 C>T, site4 C>C, site5 C> A, site6 A>T or C, and the polymorphism infonnation content (PIC) of these SNPs were in median or high polymorphism (PIC > 0.25). CONCLUSION: These SNPs at the exon2 region of the beta-LG gene were remarkably and affected milk performance traits (milk yield, protein and fat contents) in Chinese Holstein.